A total of 95 schools across WA will be closed on Tuesday due to industrial action, the Government has confirmed.

Several unions, including the State School Teachers Union, the Public Sector Union and United Voice, called for the strike on April 1 in response to what they have labelled education cuts by the Government.

State Education Minister Peter Collier said 55 primary schools and 22 high schools would close, as well as a number of education centres across WA.

The SSTU said the number of schools affected showed how strongly its members felt about the issue, but Mr Collier said the action was politically motivated and would harm students.

"This is a highly politically motivated action on the part of those three unions, and a highly irresponsible action on the part of those three unions," he said.

"They have been tireless in their efforts to ensure they could disrupt our education system, purely and absolutely as a political motive in the lead up to the half Senate election."

Unions have rejected the claim and said an application to hold the rally at Langley Park was lodged with the City of Perth well before it was known another Senate election would be needed.

Government accused of trying to intimidate teachers

The Opposition's education spokeswoman Sue Ellery said it was the Barnett Government which had introduced the cuts during the federal election.

"The State Government announced these cuts in August, in the middle of the federal election campaign, this chaos is as a direct result of the Government's own actions," she said.

"This campaign will continue because right now the Barnett Government and Mr Collier are working on the Budget in May, what we know, the Director General has directly told principals is that there are more cuts to come."

Mr Collier has described the strike as unlawful and said teachers who took part would not be paid.

"There is no right to strike in Western Australian industrial law, and no provision for protected industrial action," his spokesman said.

But Mrs Ellery said the action was not unlawful.

"It seems to me he's trying to scare people off from coming along," she said.

"It is not unlawful to protest in this country unless something's changed that I'm not aware of."

The union representing education assistants, United Voice, said Mr Collier had been trying to intimidate teachers so they would not take part in the action.

"I think the Government's trying to intimidate school staff, they're trying to intimidate parents because they know they're on the wrong side of this argument," said United Voice spokeswoman Carolyn Smith.

That is a 55 per cent increase in funding since 2008. That is from $2.8 billion to $4.4 billion, that included a seven per cent increase in funding last year.

Education Minister Peter Collier

"They know the people of Western Australia are concerned about quality education, they want good schools, they want good education for their kids.

"People of Western Australia know that this Government has cut programs, has you know led to bigger class sizes and they're affecting the education of our kids."

Mr Collier said overall funding for schools in WA had increased significantly since the Liberals took Government in 2008.

"What we've got here is a significant increase in funding in education in Western Australia since we took office," he said.

"That is a 55 per cent increase in funding since 2008. That is from $2.8 billion to $4.4 billion, that included a seven per cent increase in funding last year.

"Now we asked schools to tighten their belts because quite frankly that level of funding, when you had a nine per cent increase in student population, was simply unsustainable.

"Now on average that works out at a 1.5 per cent decrease in funding for the schools across the state.

"Considering the fact that we remain the highest resourced schools of any state in the nation is testament to the fact that we are very generous in terms of funding our schools.

"With regard to education assistants, we have by far the highest number of education assistants than any state in the nation, our education assistants have gone up from 4,500 in 2006 to over 7,500 currently, prior to the reduction this year.

"When we took office, when Mark McGowan was education minister, teachers were the lowest paid teachers in the nation, that is fact."